Air primer for burners



VALJEAN AIR PRIMER FOR BURN ERS Filed June 25, 1931 Patented Mar. 15,1932 UNITED STATES PATENT OFFICE BEN VALJEAN, OF LANSING, MICHIGAN,ASSIGNOR TO MOTOR WHEEL CORPORATION, OF LANSING, MICHIGAN, A CORPORATIONOF MICHIGAN AIR PRIMER FOR BURNERS Application filed June 25,. 1931.

Not only in combustion apparatus generally but'in connection with oilburners particularly a greater air supply is required during thepreliminary sta es of combustion when generation of gases rom the-liquidoil is taking place .in a cool burner than'later when the burner hasbecome heated.

In the operation of an oil burner of the carburetor type, for instance,asset forth in my Patents Nos. 1,512,869 and 1,639,202, after the oil isignited the generation is at first comparatively sluggish, increasing asthe carburetor or burner bowl becomes heated and the natural draftincreases the air supply through the apertured walls of the burner. Theprimary function of the carburetor bowl is to pre-mix the generated gaswith air in readiness for combustion which normally takes place outsidethe bowl in a combustion chamber, and the size of the air inlets areproportioned to effect this result." However, in order to heat the bowland secure speedy generation of gas from theoil at the start, it hasbeen thought necessary to enlarge the air inlet holes beyond therequirements of normal operation in order to effect combustion withinthe bowl during the initial stages.

The present invention has for its primary purpose the obtaining ofpreliminary combustion within the carburetor bowl by the admission ofauxiliary air until sufiicient heat is attained to generate the oilsupply into gas and then. by cutting off the extra air supply,eliminating combustion within the bowl and substituting the normaldesired carburetion or pro-mixing action.

The invention has for a further purpose the hastening of generation bysupplying to the burner interior during the cool-period, when the usualair supply is inadequate, an auxiliary priming supply of air. whichauxiliary air is gradually cut off as the burner becomes heated and theinduced draft through the apertured walls of the burner suppliessufficient air to maintain normal operation.

In order that the invention may be readily understood. the accompanyingdrawings and the following description predicated thereon set forth apreferred form of the device.

Serial No. 546,828.

quantities properly proportioned to maintain proper carburetion of thegases generated from a supply of oil indicated at 13 ,in the pan 14:,the oil being supplied through the pipe 15. The invention, however, isnot limit- .ed to this particular type of burner.

For the purpose of supplying additional air to the burner during theincipient stages of generation and combustion a tubular priming device16, preferably of L shape and comprising a horizontal portion 17 and avertical portion 18, has its horizontal portion tapped into the burnerat 19.

The vertical extension of the primer is provided with a valve seat at20, with which cooperates a valve member 21 guided by a stem 22 within adownward projection 23 of the device. valve is limited by its contactwith the valve seat 20. while its upward movement and disassembly iscontrolled by a setscrew 24.

Intermediate its length the valve stem is shouldered at 25, the lowerface of which shoulder is engaged by the movable end 26 of a bi-metallicthermostat anchored at 27 in the tubular chamber formed by thehorizontal portion 17 of the device and thus exposed'to the heat withinthe burner 11.

The relation of the shoulder 25 and the thermostat 26 is such that whenthe burner is cool the parts occupy the position indicated in Fig. 2,the weight of the valve being sustained by the movable arm 26 of thethermostat, and when the burner becomes heated the thermostat arm bendsdownwardly permitting the valve to subside by force of gravity and thevalve head 21 to contact the seat 20,

The downward movement of the thus closing the valve against the entranceof air at the open end of the vertical portion of the device.

At 28 the vertical wall of the device is provided with one or more smallbleeding apertures which remain open and serve a purpose hereinafterreferred to.

Until the burner becomes heated to a substantial extent after ignitionof the oil within the pan the parts occupy the position shown in Fig. 2,an auxiliary supply of air to the burner being furnished through thedevice. As the temperature in the burner increases and the flow of airthrough the apertures 12 increases, the thermostat bar gradu ally bendsdownward permitting the valve 21 to close graduall until when the burneris in normal operation the valve is entirely closed. Reverse operationtakes place when the supply of oil is shut off save for the maintenanceof the small uantity in the pan as a pilot, the gradual coo ing of theburner will permit a progressive opening of the valve whereby themaintenance of a smokeless pilot flame is assured.

After the closing of the valve 21 upon its seat 20, there is a tendencyof the mixture of oil vapor and air to eddy into the interior of thepriming device, with the possibility of condensation and a gummy depositcausing the valve to stick. The provision of the apertures 28 produces ableeding action of air into and through the device to the burner in asmall quantity sufiicient to scavenge the same of the products ofcombustion, thus keeping the same free of deposit.

It has also been found that where burners of the carburetor type areemployed with one of the cheaper or heavier oils as fuel, the generationof the gas tends to form a deposit of coke in the bottom of the bowl;this for the reason that the normal introduction of air at the inlets isintentionally suflicient only to effect premixture and inadequate tosupport combustion within the bowl.

By the introduction of auxiliary air when the burner is on low fire,combustion and elimination of this carbon deposit may be secured. I

To efi'ect this result it is desirable that the incoming stream ofauxiliary air be directed upon the carbon deposit or that portion of thebowl, usually the bottom, where the deposit would otherwise form, and tothis end the air port itself is appropriately located or suitable meanssuch as a d flector 29 may be employed for guiding the incoming airtowards and upon the deposit.

It is to be understood also that while the employmentof a slow-actingthermostat is illustrated and described by reason of its simplicity,other forms of thermostat may be used whether acting gradually orinstantaneously, the essence being the control of the auxiliary airsupply by the heat of the burner,

I claim:

1. An oil burner provided with an oil inlet, air inlet ports, anauxiliary air inlet, and means controlled by the degree of heat withinthe burner to open and close the auxiliary inlet gradually with thelowering and raising of the temperature in the burner.

2. An oil burner provided with an oil inlet, air inlet ports, anauxiliary air inletdevice comprising a tubular member extending fromwithout into the burner, a valve operable to close the inlet, and athermostat subject to burner heat and acting upon the valve to close thesame as the burner becomes heated.

3. An oil burner provided with an oil inlet, air inlet ports, anauxiliary air inlet device comprising a tubular member extending horizontally from without into the burner, a valve operable to close theentrance to the, device, a thermostat disposed within the device andsubject to burner heat with" its movable portion acting upon the valveto close the same as the burner becomes heated.

4. An oil burner of the carburetor type provided with an oil pan, an oilinlet, air inlet ports, an auxiliary air inlet, and means controlled bythe degree of heat within the burner to open and close the auxiliaryinlet gradually with the lowering and raising of the temperature in theburner.

5. An oil burner of the carburetor type provided with an oil pan, an oilinlet, air inlet ports, an auxiliary air inlet device comprising atubular member extending from without into the burner, a valve operableto close the inlet, and a thermostat subject to burner heat and actingupon the valve to close the same as the burner becomes heated.

6. An oil burner of the carburetor type provided with an oil inlet, airinlet ports, an-auxiliary air inlet device comprising a tubular memberextending horizontally from without into the burner, 21 valve operableto close the entrance to the device, a. thermostat disposed within thedevice and subject to burner heat with its movable portion acting uponthe valve to close the same as the burner becomes heated, and a bleedingaperture to admit a modicum of scavenging air to and through the devicewhen said inlet valve is closed.

7. An oil burner of the carburetor type provided with an oil inlet, airinlet ports, an auxiliary air inlet device comprising an L-shapedtubular member having a horizontal discharge portion extending into theburner and a vertical'inlet portion without the burner, a valve operableto close the inlet to the device by gravity, a thermostatic bar disposedwithin the horizontal portion and subject to burner heat with itsmovable portion underlying the valve and yielding to permit the closingof the valve gradually as the burner becomes heated.

' arranged to 8. An oil burner of the carburetor type provided with anoil inlet, air inlet ports, an auxiliary air inlet device comprising anL- shaped tubular member having a horizontal discharge portion extendinginto the burner and a vertical inlet portion without the burner, a valveoperable to close the inlet to the device by gravity, a thermostatic bardisposed within the horizontal portion and subject to burner heat withits movable portion underlying the valve and yielding to permit theclosing of the valve radually as the burner becomes heated, an ableeding aperture to admit a modicum of scavenging air to and throughthe device when said inlet valve is closed.

9. An oil burner provided with an oil inlet, air inlet ports, anauxiliary air inlet, means controlled by the degree of heat within theburner to open and close the auxiliary inlet gradually with the loweringand raising of the temperature in the burner, and means direct the airupon the bottom of the burner.

10. An oil burner of the carburetor type provided with an oil pan, anoil inlet, air inlet ports, an auxiliary air inlet, means controlled bythe degree of heat within the burner to open and close the auxiliaryinlet gradually with the lowering and raising of the temperature in theburner, and means arranged to direct the air upon the bottom of theburner.

provided with an oil inlet, air inlet ports, an auxiliary air inletdevice comprising a tubular, member extending horizontally from withoutinto the burner, a valve adapted to close the entrance to the device, athermostat disposed within the device and subject to burner heatlwithits movable portion acting upon the valve to close the same as theburner becomes heated, and a bleeding aperture to v admit a modicum ofscavenging air to and through the device when said inlet valve isdirecting the auxiliary closed, and means for air downwardly upon theburetor bowl. I

12. An oil burner of the carburetor type provided with an inlet ports,

ottom of the caroil pan, an oil inlet, air an auxiliary air inlet, andmeans directing the air therefrom upon the coke deposits in the burnerto consume them while the burner is on low fire, and means for closingthis auxiliary inlet when the burner is on high fire.

In testimony whereof I have hereunto subscribed my name.

BEN VALJEAN.

- 11. Anoil burner of the'carburetor type controlled by the degree ofheat produced at the burner to open and close the auxiliary inlet, theauxiliary inlet being opened only when the temperature of the burner istoo low for full fire generation.

13. An oil burner provided with an oil I inlet, air inlet ports, anauxiliary air inlet and means for opening the auxiliary inlet to admit aspecial stream of air for freeing the pilot fire from smoke, this inletwhen the burner is on high fire.

14. An oil burner provided with an oil inlet, air inlet ports, anauxiliar air inlet,

means for opening the auxiliary air inlet and and means for closing

